Variations in T1 and T2 due to MRI contrast agents: effect on image contrast

Author:

Rao, Navalgund

Abstract:

The pharmacokinetic behavior of MRI contrast
agents determines the temporal variation of
T1 and T2 values in tumor and normal tissues.
In most cases these variations occur rapidly
during the first few minutes after contrast
injection. We have developed a model to study
the effect of TI and T2 variations during image acquisition for a spin-echo pulse sequence. The method is based on the understanding that the Free Induction Decay (FID) measurements in MRI are samples of the 2D fourier space along k trajectories, determined by the gradient fields. With the experimental TI and T2 data for Gd-DTPA in rat liver and liver tumor, the effect of temporal variations of TI and T2 on the final image contrast is illustrated for standard spin-echo imaging pulse sequence (Refer to PDF file for exact formulas).